A variety of contraceptive devices are currently available. However, each is accompanied by certain drawbacks. For example, diaphragms require careful fitting, usually by a trained physician, rendering them ill-suited for underdeveloped countries, where needed most. Further, condoms can tear, spent condoms must be disposed of and can feel unnatural.
As safe as today's “pill” is for most women, it is still not safe for all. In particular, women over 35, who are heavy smokers (more than 14 cigarettes a day), are obese, or have (or have a history of) diabetes, high blood pressure, high cholesterol, cancer of the breast or sex organs, blood clots, heart attack or stroke have a significantly increased risk of serious side effects (including a heart attack or stroke) while taking the pill. This risk increases with age. Less severe side effects, including nausea and vomiting, breast tenderness and engorgement, acne, fluid retention, weight gain, increased vaginal discharge and breakthrough bleeding, can be experienced, particularly when a female first takes the pill.
Spermicidal contraceptives, which typically contain surfactants, can negatively affect normal vaginal flora. For example, frequent use of N-9 as a vaginal contraceptive/microbiocide has been associated with an increased risk of vaginal or cervical infection, irritation, or ulceration (Niruthisard et al., Sex Transm Dis. 18:176-79 (1991); Rekart, Defic Syndr. 5:425-27 (1992); Roddy et al., Int J STD & HIV. 4:165-70 (1993); Weir et al., Genitourin Med. 71:78-81 (1995)) which can enhance the susceptibility of the ectocervical epithelium and the endocervical mucosa to HIV-1 infection (Augenbraun et al. Infect Dis Clin North Am. 8:439-48 (1994), Weir et al., Genitourin Med. 71:78-81 (1995); Kreiss, JAMA. 268:477-82 (1992)).
There is a need for new safe and effective contraceptives.